tbuckley/cabot-search huggingface dataset:
Abstract 3197: Adoptive T cell therapy using IL-7 and IL-15 expanded HER2-specific CD4 T cells for metastatic breast cancer
Authors: Namrata Gautam, Krithika Kodumudi, Colin Snyder, Amber Beyer, Ricardo Costa, Heather Han, Brian Czerniecki
Journal: Cancer Research (2023)

Abstract BACKGROUND: Adoptive cell therapy (ACT) has had limited success due to low T cell infiltration in breast cancer (BC) patients. We have shown that administration of class II HER2 peptide pulsed type I polarized dendritic cell (DC1) vaccines leads to increase in CD4 T cells in the periphery of BC patients. In this study, we investigated the feasibility of expanding CD4 T cells from peripheral blood mononuclear cells (PBMC) of HER2-DC1 vaccinated BC patients. METHODS: PBMCs from BC patients receiving HER2-DC1 vaccines were used for CD4 T cell expansion. PBMCs were co-cultured with HER2-DC1 at 10:1 ratio for initial activation followed by expansion with cytokines- IL-2 and IL-7 or IL-15. Expanded T cells were assessed for immune marker phenotyping by flow cytometry and TCRvb analysis. For TCRvB analysis, pre, post DC1, IL-7 and IL-15 expanded CD4 T cells were pelleted for DNA isolation and sequenced using Immunoseq Analyzer platform. In addition, we investigated the in vivo efficacy of adoptively transferred mouse IL-7/IL-15 expanded Her2 specific CD4 T cells in HER2+ TUBO mouse model. RESULTS: Co-culturing of patient PBMCs with HER2-DC1 in the presence of cytokines IL-2, IL-7 and IL-15 expanded CD4 T cells ranging from 8-43 fold expansion in different samples with 92-98% CD4 phenotype. CD4 T cells expanded in IL-7 had stem like memory phenotype while IL-15 skewed to terminally differentiated CD4 T cells. IL-7 expanded T cells had significantly higher Tim3 and Ox40 expression, and effector memory proportion as compared to the IL-15 expanded T cells. Restimulation of expanded T cells with HER2 pulsed DCs showed HER2 specificity as measured by increased interferon-gamma production We identified top five clones in PBMCs from DC1-HER2 vaccinated BC patients compared to baseline. We observed differential abundance of TCR clones under IL-7 and IL-15 conditions and identified unique clones for IL-7 and IL-15. ACT using a combination of IL-7 and IL-15 expanded mouse CD4 T cells led to 50% tumor regression in HER2+ model. CONCLUSION: These studies demonstrate that HER2 specific CD4 T cells can be successfully expanded from HER2-DC1 vaccinated patients. Post HER2 DC1 vaccine can generate a pool of antigen specific CD4 T cells and may offer a promising ACT for HER2 BC. Further studies are warranted to demonstrate the efficacy in the clinical setting. Citation Format: Namrata Gautam, Krithika Kodumudi, Colin Snyder, Amber Beyer, Ricardo Costa, Heather Han, Brian Czerniecki. Adoptive T cell therapy using IL-7 and IL-15 expanded HER2-specific CD4 T cells for metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3197.
Abstract 5184: Anti-HVEM mAb therapy improves antitumoral immunity both <i>in vitro</i> and <i>in vivo</i>, in a novel transgenic mouse model expressing human HVEM and BTLA molecules challenged with HVEM expressing tumors
Authors: Laurent GORVEL, Clemence Demerle, Marielle Mello, Sonia Pastor, Clara Degos, Ana Zarubica, Fabien Angelis, Frederic Fiore, Jacques Nunes, Bernard Malissen, Laurent Greillier, Geoffrey Guittard, Herve Luche, Fabrice Barlesi, Daniel Olive
Journal: Cancer Research (2023)

Abstract TNFRF-14/HVEM is the ligand for BTLA and CD160 negative immune co-signaling molecules as well as viral proteins. Its expression is dysregulated with an overexpression in tumors and a connection with tumors of adverse prognosis. We developed C57BL/6 mouse models co-expressing human huBTLA and huHVEM as well as antagonistic monoclonal antibodies (mAbs) that completely prevent the interactions of HVEM with its ligands. Here, we show that the anti-HVEM18-10 mAb increases primary human αβ-T cells activity alone (CIS-activity) or in the presence of HVEM-expressing lung or colorectal cancer cells in vitro (TRANS-activity). Anti-HVEM18-10 synergizes with anti-PD-L1 mAb to activate T cells in the presence of PDL-1 positive tumors, but is sufficient to trigger T cell activation in the presence of PD-L1 negative cells. In order to better understand HVEM18-10 effect in vivo and especially disentangle its CIS and TRANS effects, we developed a knock-in (KI) mouse model expressing human BTLA (huBTLA+/+) and a KI mouse model expressing both human BTLA and human HVEM (huBTLA+/+/huHVEM+/+ (DKI)). In vivo pre-clinical experiments performed in both mouse models showed that HVEM18-10 treatment was efficient to decrease human HVEM+ tumor growth. In the DKI model, anti-HVEM 18-10 treatment induces a decrease of exhausted CD8+ T cells and regulatory T cells and an increase of Effector memory CD4+ T cells within the tumor. Interestingly, mice which completely rejected tumors (± 20%) did not develop tumors upon re-challenge in both settings, therefore showing a marked T cell-memory phenotype effect. Altogether, our preclinical models validate anti-HVEM18-10 as a promising therapeutic antibody to use in clinics as a monotherapy or in combination with existing immunotherapies (anti-PD1/anti-PDL-1/anti-CTLA-4). Citation Format: Laurent GORVEL, Clemence Demerle, Marielle Mello, Sonia Pastor, Clara Degos, Ana Zarubica, Fabien Angelis, Frederic Fiore, Jacques Nunes, Bernard Malissen, Laurent Greillier, Geoffrey Guittard, Herve Luche, Fabrice Barlesi, Daniel Olive. Anti-HVEM mAb therapy improves antitumoral immunity both in vitro and in vivo, in a novel transgenic mouse model expressing human HVEM and BTLA molecules challenged with HVEM expressing tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5184.
Abstract 4122: TIL-containing patient-derived explant cultures reveal role of metformin on antigen presenting cell activation
Authors: Rita J. Turpin, Ruixian Liu, Pauliina Munne, Aino Peura, Jenna Rannikko, Gino Philips, Natasha Salmelin, Elina Hurskainen, Ilida Suleymanova, Minna Mutka, Tuomo Meretoja, Johanna Mattson, Satu Mustjoki, Päivi Saavalainen, Diether Lambrechts, Jeroen Pouwels, Maija Hollmén, Juha Klefström
Journal: Cancer Research (2023)

Abstract Globally, breast cancer is among the most diagnosed cancer types for women. Current and upcoming breast cancer therapies are being investigated in combination with compounds that stimulate an immune response, but whether the therapeutic agents themselves have unexpected immunomodulatory effects is often overlooked. Here, we have developed a method to grow 3D cultures of intact fragments of patient-derived tissue (Patient-Derived Explant Cultures; PDECs) to assess the preclinical potential of studying human tumor cells and immune cells simultaneously ex vivo Single cell sequencing, flow cytometry, gene expression profiling and cytokine profiling data show that the tumor immunocontexture is conserved in PDECs and that these resident immune cells respond to distinct immune stimulus We performed gene expression profiling, flow cytometry, and cytokine profiling of drug-treated human explants and found that metformin has antitumor potential through the activation of antigen presenting cells. We further validated in vitro that metformin-mediated APC activation is largely through mitochondrial respiration inhibition irrespective of the presence of tumor cells. Our PDEC platform highlights the preclinical potential of ex vivo explants by simultaneously offering information of tumor and immune cell toxicity and mechanism. Citation Format: Rita J. Turpin, Ruixian Liu, Pauliina Munne, Aino Peura, Jenna Rannikko, Gino Philips, Natasha Salmelin, Elina Hurskainen, Ilida Suleymanova, Minna Mutka, Tuomo Meretoja, Johanna Mattson, Satu Mustjoki, Päivi Saavalainen, Diether Lambrechts, Jeroen Pouwels, Maija Hollmén, Juha Klefström. TIL-containing patient-derived explant cultures reveal role of metformin on antigen presenting cell activation. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4122.
Abstract 6796: PoxSTG, a novel chimeric poxvirus with improved oncolytic potency
Authors: Philippe Erbs, Annie Findeli, Johann Foloppe, Juliette Kempf, Isabelle Farine, Baptiste Moreau, Julie Hortelano, Christelle Pichon, Jules Deforges, Eric Quemeneur
Journal: Cancer Research (2023)

Abstract Oncolytic virus (OV) therapy has emerged as a promising approach for cancer treatment with the potential to be less toxic and more efficient than classic cancer therapies. Various types of OVs in clinical development, including Vaccinia virus (VACV)-derived OVs, have shown good safety profiles, but limited therapeutic efficacy as monotherapy in some cancer models. Many different methods have been employed to improve the oncolytic potency of OVs. We used a directed evolution process, pooling multiple species of orthopoxviruses to generate chimeric poxviruses with increased oncolytic properties. Through selective pressure by successive passages on human tumor cells, a new chimeric oncolytic poxvirus, named PoxSTG, was derived. The chimeric viral genome contains, in addition to sequences from several strains of Vaccinia virus, sequences of Rabbitpox virus and Cowpox virus. Compared with its parental viruses, PoxSTG has demonstrated superior oncolytic characteristics, and was notably attenuated in normal primary cells. PoxSTG has superior secretion of extracellular-enveloped virus (EEV) compared to all parental strains inducing higher dissemination of the virus into the tumors and more resistance to neutralization. PoxSTG was saved and showed potent antitumor effects in several syngeneic and xenograft mouse models of cancers. Furthermore, PoxSTG exerted low-dose antitumor effects in virus-injected and non-virus-injected distant tumors in a CRC xenograft model, demonstrating strong virus spread to distant tumors. All these data demonstrate the potential of PoxSTG as a novel therapeutic agent for cancer treatment. Citation Format: Philippe Erbs, Annie Findeli, Johann Foloppe, Juliette Kempf, Isabelle Farine, Baptiste Moreau, Julie Hortelano, Christelle Pichon, Jules Deforges, Eric Quemeneur. PoxSTG, a novel chimeric poxvirus with improved oncolytic potency. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6796.
Abstract 2483: Attenuated <i>Salmonella</i> blocks cancer metastasis by activating NK cells in an IFN-γ-dependent manner
Authors: Li Rong, Qiubin Lin, Shuhai Lin, Guo Fu, Jiandong Huang
Journal: Cancer Research (2023)

Abstract Introduction and Objectives: The recent remarkable clinical results of cancer immunotherapies, such as immune checkpoint blockade and chimeric antigen receptor T cells (CAR-T), has sparked a great deal of enthusiasm in manipulating the immune response in the fight against cancer. Bacterial cancer therapies represent an alternative approach to targeting solid tumors for evoking anti-tumor immune responses. As a facultative anaerobic pathogen that can penetrate and colonize solid tumors, Salmonella typhimurium gained lot of interest in the investigation of bacterial cancer therapies and can exert its intrinsic antitumor activity by directly inducing systemic immune responses. However, most bacterial cancer therapies, including salmonella-based cancer therapies, have mainly focused on the suppression of already established tumors rather than metastasis. Metastasis accounts for 90% of cancer related deaths and blocking of metastatic cascade has critical clinical impact. However, the clinical drug development for cancer treatment, including cancer immunotherapies, is evaluated largely depending on their ability to cause tumor shrinkage and ignores the effect on metastasis as it has proven challenging to target. Therefore, there is an urgent need for novel therapeutic strategies and agents targeting metastasis. Experimental Procedures and Outcomes: Using an attenuated Salmonella typhimurium strain YB1 engineered by our lab, we have found a potent suppressive effect of attenuated salmonella on cancer metastasis, regardless of cancer types and genetic background, by evoking strong anti-metastatic immune response. Further study showed that suppression of cancer metastasis by attenuated Salmonella only requires the innate immune response. Among the many induced cytokines, we identified IFN-γ as an indispensable factor for inhibiting cancer metastasis. Based on CyTOF (mass cytometry or cytometry by time of flight) analysis of the innate immune responses after Salmonella treatment and antibody-mediated cell depletion, we further demonstrated that NK cells are the major factor involved in Salmonella-provoked metastasis suppression. We found that IFN-γ was mainly produced by NK cells during early Salmonella infection, and in turn, IFN-γ promoted the accumulation, activation and cytotoxicity of NK cells. The IFN-γ-dependent NK cells directly eliminated newly accumulated cancer cells in the lung to block the cancer metastasis cascade in response to the Salmonella treatment. Citation Format: Li Rong, Qiubin Lin, Shuhai Lin, Guo Fu, Jiandong Huang. Attenuated Salmonella blocks cancer metastasis by activating NK cells in an IFN-γ-dependent manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2483.
Abstract 5236: Functional analysis of variants of uncertain significance of the <i>MSH6</i> mismatch repair gene
Authors: Elizabeth Szabo, Emily Blackburn, Patrick Pagano, Abhijit Rath, Christopher Heinen
Journal: Cancer Research (2023)

Abstract Lynch syndrome (LS) is a hereditary condition that increases patients’ lifetime risk of cancer, primarily colorectal cancer. LS is caused by germline mutations in mismatch repair (MMR) genes, MLH1, MSH2, MSH6, and PMS2. Identification of these mutations is important in LS diagnosis in order to guide treatment plans and preventative care for patients’ and their families. However, the consequences of some variants in these genes are not immediately obvious, granting them classification as variants of uncertain significance (VUS). Half of known variants in the MMR gene MSH6 are VUS and, thus, the goal of my project is to provide evidence to help better determine their pathogenic significance. Laboratory functional analysis to determine whether these variants disrupt MMR function in human cells can provide such evidence toward this goal. We have previously used CRISPR gene editing to recreate variants in the endogenous loci for the MMR genes MSH2 and MLH1 in human embryonic stem cells (hESC) in order to test their effects on MMR function in a cellular environment. We will now use test whether this approach can be used to study MSH6 VUS. Using these edited hESC lines we are examining the impact of the variants on RNA and protein stability, repair of DNA microsatellites, which is a hallmark of normal MMR function, and induction of the MMR-dependent DNA damage response. Using a panel of known MSH6 pathogenic and benign controls, we will calibrate these functional assays in order to associate functional performance with likelihood of pathogenicity. We will next test a separate panel of known controls to validate these assays. Finally, we will examine up to 35 VUS. With this compilation of data, we will convert the results into a quantitative Odds of Pathogenicity value. This Odds of Pathogenicity score can be used by expert variant interpretation committees to help readily reclassify these variants, and provide a clearer diagnosis for these suspected Lynch syndrome patients. Citation Format: Elizabeth Szabo, Emily Blackburn, Patrick Pagano, Abhijit Rath, Christopher Heinen. Functional analysis of variants of uncertain significance of the MSH6 mismatch repair gene. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5236.
Abstract 344: PKC-ι is a simultaneous modulator of the sonic hedgehog and the FAK/paxillin pathways in medulloblastoma
Authors: Luke Lajmi, Sloan Breedy, Aaron Todman, Wishrawana S. Ratnayake, Mildred Acevedo-Duncan
Journal: Cancer Research (2023)

Abstract Medulloblastoma is the second most common childhood cancer, behind leukemia, and the most common pediatric brain tumor, comprising 20% of all childhood brain cancers. Our data demonstrated the effectiveness of atypical protein kinase C (aPKC) inhibitors 2-acetyl-1,3-cyclopentanedione (ACPD), 3,4-diaminonapthalene-2,7-disulfonic acid (DNDA), 5-amino-1-2,3-dihydroxy-4-(methylcyclopentyl)-1H-imidazole-4-carboxamide (ICA-1S), and 8-hydroxy-1,3,6-naphthalenetrisulfonic acid (ζ-Stat) to significantly decrease cell proliferation with increasing inhibitor concentration. The continuation of this study involves examining the oncogenic role of PKC-ι as a key molecule that acts as a central modulator of the activities of the sonic hedgehog (SHH) pathway and the focal adhesion kinase (FAK)/paxillin pathway. Our data will demonstrate the toxic effects of ICA-1S, more so than the other three inhibitors, through WST-1 assays as well as Western blot data that shows the effectiveness of ICA-1S to selectively downregulate the phosphorylation of PKC-ι, by 42% in D283 cells and 20% in Daoy cells, which resonantly impacts the various signaling proteins that govern the SHH and FAK/paxillin pathway across D283, D341, and Daoy medulloblastoma cell lines. Phosphorylation of FAK was reduced in D283 by 25%, 30% in D341 cells, and 15% in Daoy cells upon treatment with ICA-1S. This indicates that even though these cell lines have different mutations, they appear to proliferate by similar signaling pathways. Immunoprecipitation studies showed that simultaneous downregulation of PKC-ι and PKC-ζ in the D341 cell line is the result of the association of PKC-ι and PKC-ζ, indicating they may directly regulate each other’s catalytic activities. Furthermore, ICA-1S was shown to reduce the association of PKC-ι and PKC-ζ by over 75% in D341 cells. Future studies will be conducted to determine the effect of aPKC inhibitors on additional downstream proteins in the FAK/paxillin pathway and cell cycle regulation by Western blotting. We will also be investigating the effect of the inhibitors on the migratory and invasive capacity of medulloblastoma by implementing wound-healing assays and Boyden chamber assays. Citation Format: Luke Lajmi, Sloan Breedy, Aaron Todman, Wishrawana S. Ratnayake, Mildred Acevedo-Duncan. PKC-ι is a simultaneous modulator of the sonic hedgehog and the FAK/paxillin pathways in medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 344.
Abstract 5319: EU-OPENSCREEN - An open-access initiative in chemical biology to support anti-cancer drug discovery
Authors: Bahne Stechmann, Charlotte Wit
Journal: Cancer Research (2023)

Abstract Over the past two decades, an increasing number of small molecule drugs that target unique molecular changes underlying a specific cancer have been approved, and small molecule drugs represent a major therapeutic class for cancer treatment. Chemical ‘probes’ are also indispensable tools to advance our understanding of pathologies at the molecular and cellular level and to validate novel drug targets. A major bottleneck in identifying and developing these chemical compounds in academia is often access to robust disease-relevant assays, high-throughput screening platforms, comprehensive screening libraries, medicinal expertise for the hit-to-lead optimization. In order to democratize access to these resources for a broader scientific community, the publicly funded EU-OPENSCREEN (www.eu-openscreen.eu) initiative has been established with the aim to accelerate drug discovery efforts in an open-access setting in collaboration with researchers from academia and industry. EU-OPENSCREEN’s 30 expert centers offer access to their cancer target-based and phenotypic drug screening expertise, capabilities in developing disease-relevant assays and hit-to-lead optimization capabilities. The identified bioactive ‘hit’ compounds will be progressed into high-quality chemical starting points to be further developed into drug leads or chemical probes for the elucidation of mechanisms of cancer onset, progression, resistance and effects of drug therapy. All generated tool compounds and associated bioactivity data are made available to the global scientific community. Here we will present an overview of anti-cancer drug discovery projects of EU-OPENSCREEN and explain the opportunities and benefits for other international scientists to collaboratively develop novel anti-cancer drug leads and chemical probes. EU-OPENSCREEN receives funding from the European Union's Horizon 2020 and Horizon Europe research and innovation programs under grant agreements No 654248 and 101058620. Citation Format: Bahne Stechmann, Charlotte Wit. EU-OPENSCREEN - An open-access initiative in chemical biology to support anti-cancer drug discovery. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5319.